Due to sign in problems I have changed my sign in from XK John to XKJon. I have what appears to be minor under paint blistering in a small number of places on my recently acquired 2011 XK convertible no doubt caused by aluminium corrosion under the paintwork. I have extensive experience dealing with this on steel bodied cars but no experience of treating alloy bodied cars in order to halt this problem. I intend to undertake a major underbody protective programme whilst the vehicle is not being used during this corona virus crisis. I have a range of high quality treatments and etching primers from Bilt Hamber but would greatly appreciate any advice and guidance.  

Just joined the forum and am interested in your problem, as I have the same.  I bought new in 2014 an XK Signature.  At just over 12 months old the paint bubbled on the wing and it was repaired under warranty not without stress.  We keep it inside and have done to date 15000 miles.  The car is well maintained, regularly washed and waxed, and used with care.  In around last October I noticed that the paint on the roof was bubbling in the same way, also under the mirror. I rang the local branch of the dealership of the well known Company I bought it from.  I  outlined the problem and asked if they would contact Jaguar on my behalf.  They said no - out of warranty.  I contacted Jaguar myself and received the same answer, even though this is a recurring problem from the warranty period and is obviously (to me) an inherent problem.  So I shall have to look for the same solution as you. I shall have to leave this for a while though there are now other problems  which I shall post which at the moment are more pressing.   What really gives me the pig is that I bought a new van at the same time for half the price of the Jag,  it’s kept outside and has done twice the miles and the bodywork is perfect.

Peter J.